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Index > Main > my_size = my_end - my_start : INVALID use of symbol

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Necromancer13.13



Joined: 20 Apr 2008
Posts: 15
Location: Ukraine
Necromancer13.13
When I try to complile this, I get an error: my_size = my_end - my_start: INVALID use of symbol, is this normal?

All source code:

Code:
format ELF

section '.text' executable

public _start

my_start:

get_str_length:
    push    ebp
 mov     ebp,esp
     push    ecx esi
     mov     esi,dword [ebp+8]
   xor     ecx,ecx
  @@:
        lodsb
       or      al,al
       jz      @f
  inc     ecx
 jmp     @b
  @@:
     mov     eax,ecx
     pop     esi ecx
     mov     esp,ebp
     pop     ebp
 ret     4

print_msg:
     push    ebp
 mov     ebp,esp
     mov     esi,[ebp+8]
 push    esi
 call    get_str_length
      pushad
      mov     edx,eax
     mov     ecx,esi
     xor     ebx,ebx
     inc     ebx
 mov     eax,4
       int     80h
 popad
       mov     esp,ebp
     pop     ebp
 ret     4

hex2str:
       push    ebp
 mov     ebp,esp
     pushad
      mov     edi,[ebp+8]
 mov     ebx,_table
  mov     dl,al
       shr     al,4
        xlatb
       stosb
       mov     al,dl
       and     al,0Fh
      xlatb
       stosb
       popad
       mov     esp,ebp
     pop     ebp
 ret     4

  _table   db '0123456789ABCDEF'

print_hex_byte:
      push    buffer
      call    hex2str
     push    buffer
      call    print_msg
   ret

_start:
      mov     al,13h
      call    print_hex_byte
      xor     ebx,ebx
     mov     eax,ebx
     inc     eax
 int     80h

my_size = my_end - my_start

section '.data' writeable

  buffer       db 'XX',0
my_end:

    

_________________
FASM Rules!
Post 11 Jun 2008, 13:56
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vid
Verbosity in development


Joined: 05 Sep 2003
Posts: 7105
Location: Slovakia
vid
I think you cannot cross sections... ELF can be linked and sections moved around.
Post 11 Jun 2008, 14:00
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revolution
When all else fails, read the source


Joined: 24 Aug 2004
Posts: 17248
Location: In your JS exploiting you and your system
revolution
What vid means is that my_end is out of scope when fasm encounters the expression.
Post 11 Jun 2008, 14:25
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